With known apparatus for manufacturing ducts for use in HVAC systems and the like, a series of bends are made in a metal web to form a duct blank. Typically, a seam is used to close the duct blank to fully form the duct. The seam is pre-formed by aligning and then bending free edges of the partially formed duct. Typically, the duct blank is then removed from the apparatus along the line of the seam, and final closure of the pre-formed seam happens off the manufacture line to accommodate varying duct sizes and to permit the use of hand tools or separate machinery for closure. However, during removal of the duct blank from the apparatus, the free edges in the pre-formed seam tend to separate, requiring the seam to be reformed offline prior to final closure. Thus, making ducts according to the known apparatus is inefficient at least because the free edges must be manually aligned, bent, and closed.